To calculate this expression, we need to find a common denominator for the fractions first.

4/5 = 24/30
1/10 = 3/30
1/6 = 5/30
1/30 = 1/30

Now, the expression becomes:

24/30 - 3/30 + 5/30 - 1/30

Combine the numerators:

(24 - 3 + 5 - 1) / 30 = 25/30

Since 25 and 30 have a common factor of 5, the final simplified fraction is:

5/6

So, 4/5 - 1/10 + 1/6 - 1/30 = 5/6